1. Technical Field
The present invention relates to technology for providing information used on networks.
2. Description of the Related Art
Cooperation in the commitments of numerous network-based service-provision systems has lately become possible. This is because process modules that until recently had been developed independently for each service-provision system have been made into components, which has enabled using them in respective combinations. Owing to this, providing complex services by dynamically integrating numerous service-provision systems has become possible.
For example, an office worker might make travel arrangements at a company for a business trip, and the necessary travel-ticket and hotel reservations might be made automatically in accordance with what the travel arrangements entail. This could take place, for instance, by exchanging between a server for a travel agency and a server within the company messages in which reservations for transportation and lodging facilities necessary for the business trip are described in a language such as XML (extensible markup language), according to a protocol such as SOAP (simple object access protocol).
Meanwhile, in situations in which a number of service-provision systems cooperate over the Internet in their commitments, how information flowing among the service-provision systems ought to be administrated has come to be crucial. In particular, in a situation in which services are provided to a given user for whom a number of service-provision systems have made cooperative commitments, requisite information must be circulated among each of the service-provision systems, and each system must be made to share that information. On the other hand, as far as having information pertaining to users circulated among a number of service-provision systems is concerned, there will at times be such drawbacks for the users as user-private information being divulged. In short, there is a need for protecting, by a method that does not prove disadvantageous for users, personal information that flows over a network.
A method such as Microsoft™ Corp.'s “.NET My Services” is, to name one example, this sort of personal-information protection method. By this method: 1) a user's personal information is put together by a portal server; and 2) what personal information is delivered to what service-provision system is selected by the user. In this way, only personal information residing on portal servers that are trusted circulates among the service-provision systems.
Nevertheless, in situations in which messages are exchanged directly among a number of service-provision systems as mentioned above, the process modules must be designed in advance so as to enable fellow service-provision systems to cooperate. Likewise, the servers must be fitted out with process modules for judging confidence level of partner-system servers that act as message-exchange partners whenever cooperative commitments are made. The processing burden on the servers, and the development and running costs, grow consequently larger, which tends to make the price of providing the services rather high.
In situations in which personal information residing on trusted portal servers is circulated among service-provision systems, meanwhile, all users can do is select whether a portal server is trusted or not. Moreover, with this model the downside of being able to share collectively administrated user personal information among a number of service-provision systems is that there is no mechanism for sharing with other service-provision systems personal information not administrated through portal servers.